Ice or fire? Comparison of second-generation cryoballoon ablation and radiofrequency ablation in patients with symptomatic persistent atrial fibrillation and an enlarged left atrium

Introduction: We aimed to compare arrhythmia recurrence rates after second-generation cryoballoon (CB-Adv) ablation and radiofrequency (RF) ablation in patients with symptomatic persistent atrial fibrillation (AF) and left atrial (LA) enlargement. Methods and results: Persistent AF patients with LA enlargement were compared using a propensity-score-matching algorithm, and 111 patients treated with CB-Adv ablation and 111 patients treated with RF ablation were selected. The primary endpoint was the first documented >30-second arrhythmia recurrence after a 3-month blanking period. Median LA area was comparable between the RF and CB-Adv groups (24.2 vs. 24.0 cm(2), P = 0.49). In addition to pulmonary vein isolation, roof lines (RLs) with bidirectional conduction block were created in 48 patients in the CB-Adv group and 49 patients in the RF group. Midterm outcome after single procedure is characterized by arrhythmia recurrences in 47 patients in the RF group and 32 patients in the CB-Adv group (P = 0.20). There were no differences in the number of AF recurrences in the two groups (38 vs. 32, P = 0.66), but there were more instances of LA tachycardia (LAT) in the RF group than in the CB-Adv group (11 vs. 0, P < 0.01). LAT recurrence in RF patients was associated with RL creation (9 with vs. 2 without, P < 0.01). Among patients in whom a RL was created, arrhythmia-free survival was lower in the RF group than in the CB-Adv group (44.9% vs. 79.2%, P < 0.01). Conclusions: Arrhythmia recurrence rates in the two groups during midterm follow-up were comparable. RL creation during CB-Adv ablation resulted in acceptable outcomes.